• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.4
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• pp.232-241
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• 2003

The interaction of incident monochromiatic waves with N bottom-mounted porous circular cylinders is investigated in the frame of three-dimensional linear potential theory. The fluid domain is divided into N+l regions i.e. a single exterior region and N interior regions, and the diffraction potential in each fluid region is expressed by an eigenfunction expansion method (Williams and Li,2000). The analytic results show that the porous structure reduces both the wave forces and the run-up wave around the cylinder. To verify the developed model, the systematic model test with a line array of porous cylinders is conducted at the wave tank (30m$\times$7m$\times$1.5m). The analytic results are in good agreement with the experimental results within measured frequency range. It is concluded that the breakwater constructed with an array of porous circular cylinders shows the performance of an effective wave barrier together with the seawater-exchange effect and is considered to have vast potentials for the use of seawater-exchanging breakwater in the future.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.6
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• pp.1069-1076
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• 2019

With the development of information and communication technology, the military's battle environment is changing greatly to network centric warfare in where weapon system is connected in a network and carries out mission by exchanging the real-time data. The core of the network centric warfare is Tactical Data Link(TDL) system, and subscribers of TDL exchange tactical information in real time through wireline, wireless and satellite network to share the battlefield situation. The amount of data sent and received through TDL inevitably increase as military's weapon systems equipped with TDL systems increase over time and the performance of communications equipment improves. This study proposes ways to improve the transmission speed and processing capacity of the TDL system by improving the Data Link Processor.

• Korean Institute of Interior Design Journal
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• v.24 no.3
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• pp.38-47
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• 2015

This study evaluated non-liturgical space of catholic churches based on the four principles of universal design; accessible design, supportive design, safety-oriented design, and adaptable design. To design those spaces in terms of supportive design principle, diaper exchanging station needs to be placed in the restroom. Findings of this study are as follows: In terms of accessible design, valid width of entrance door to each room(more than 800mm), installation of elevator, height of riser in the stair, and width of step board were appropriate, but there were many spaces where door sils were not removed. In terms of supportive design, notice board at teacher's room and installation of storage closet, and width of passage to office(more than 1,200mm) were also appropriate, but storage closet at a meeting and prayer room, and space for storing flowers appeared inappropriate. To design those spaces in terms of supportive design principle, diaper exchanging station needs to be placed in the restroom. In terms of safety-oriented design, installation of round-edged furniture, use of non-slip flooring material, installation of safety emergency bell at a restroom, and installation of wall handle were required. In terms of adaptable design, space for wheelchair users at each room, installation of the furniture that can adjust the height, installation of desk with different height at an office, installation of toilet and basin considering children were considered to be necessary.

• Journal of KIISE:Information Networking
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• v.35 no.4
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• pp.311-317
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• 2008

This paper proposes a session key exchange scheme for providing secure communication between Vehicles and Infrastructure in VANET. In the current VANET environment, IEEE 802.11i or PKI based mechanism is used to provide secure communication between V2I. However, since the vehicles and the frequent changes of network topology, VANET nodes have some difficulties to exchange the session key using IEEE 802.11i or PKI method. In the proposed scheme, Local Router is newly defined for exchanging the session key between moving vehicles and infrastructure. A session key is generated by XOR operation based on the random values between Local Router and OBU. As a result, the proposed scheme has a noticeable advantage on the fastness of key exchange by exchanging session keys between LR and OBU.

• Korean Institute of Interior Design Journal
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• v.14 no.6 s.53
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• pp.252-259
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• 2005

A modern museum has been changed from a passive place for simply exhibiting arts and antique collections to an interactive place for learning and experiencing culture and information. Such a functional change of the modern museum requires not only reorganizing fundamental characteristics of the modern museum, but also reforming organization of management teams, changing attitudes of staffs and assigning new roles to staffs for accepting the new thought and approach of visitors. That is, the function of the modem museum is not limited to collect arts and antique collections. The fundamental change of the modern museum further requires using the collections as a tool or a medium to provide a cultural exchange between the visitors and the museum, and to give new experience and information to the visitors. After proposing discussion that ' how, what, who is related to the museum? ', the way of thinking the museum is changed from ' collection ' to ' communication '. The change of the modern museum improves an educational role of the museum, and makes the museum as a communicator exchanging information and experience with visitors. In the last analysis, the modern museum is not just an exhibition medium that simply transfers information of the exhibition mediums to public. The modem museum is also a communication medium in order to collect information and transfer the collected information to the visitors. That is, the modern museum should provide various exhibition and communication mediums to the visitors for exchanging information and cultural experience. Therefore, the modern museum requires additional functions processing information suitable to the present environment and level of the museum, and transferring the information to public.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2823-2829
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• 2011

All of the government, private enterprises, and local governments are promoting the spread of electric vehicles to reduce carbon emissions depending on the green growth policy of the government that began in 2009. Due to this background, the prevalence of electric cars is being spread. However, the efficient management and operation through the exchanging information between electric vehicles and charging infrastructure, as well as the development of electric vehicles are essential to disseminate them. In this paper, we present a service framework for exchange of information between electric vehicles and charging infrastructure, and propose a communication method to meet it. To do this, we propose the most appropriate communication method through the performance evaluation by identifying and comparing the existing wireless communication methods can be applied to exchange information between electronic vehicles and EV charging infrastructure.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2001.10a
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• pp.281-285
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• 2001

This study was carried out to improve the performance of heat recovery device attached to exhaust gas flue connected to combustion chamber of greenhouse heating system. Three different units were prepared for the comparison of heat recovery performance; AB-type(control unit) is exactly the same with the typical one fabricated for previous study of analyzing heat recovery performance in greenhouse heating system, other two types(C-type and D-type) modified from the control unit are different in the aspects of airflow direction(U-turn airflow) and pipe arrangement. The results are summarized as follows; 1. In the case of Type-AB, when considering the initial cost and current electricity fee required for system operation, it is expected that one or two years at most would be enough to return the whole cost invested. 2. Type-C and Type-D, basically different with Type-AB in the aspect of airflow pattern, are not sensitive to the change of blower capacity with higher than $25\;m^{3}/min$. Therefore, heat recovery performance was not improved so significantly with the increment of blower capacity. This is assumed to be that air flow resistance in high air capacity reduces the heat exchange rate as well. Never the less, compared with control unit, resultant heat recovery rate in Type-C and Type-D were improved by about 5% and 13%, respectively. 3. Desirable blower capacity for these heat recovery units experimented are expected to be about $25\;m^{3}/min$, and at the proper blower capacity, U-turn airflow units showed better heat recovery performance than control unit. But, without regard to the type of heat recovery unit, it is recommended that comprehensive consideration of system's physical factors such as pipe arrangement density, unit pipe length and pipe thickness, etc., are required for the optimization of heat recovery system in the aspects of not only energy conservation but economic system design.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.27-36
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• 2009

Standard electronic tax invoice is a document standard for electronically exchanging tax invoices, which have been used in the form of paper for proofing business transactions. This standard focuses on the aspect of exchanging electronic documents between businesses and between businesses and NTS(National Tax Service), so it is limited in expressing semantics and contexts of financial information explicitly and economically for reusing them after their exchanges. Above all, it is needed to consider that they can be employed to various applications of businesses including financial reporting and auditing because they contain basic financial information about taxes and that they are reported to NTS. In this perspective, this paper compares and analyzes how to compose standard electronic tax invoice documents in XBRL with concrete examples, focused on the expressability and applicability, and discusses the possibility of XBRL-based standard electronic tax invoices.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.8
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• pp.665-675
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• 2016

With the development of active phased array radar technology in recent years, active phased array antennas, which digitally combine signals received from subarray units using dozens of digital receiver, have been developed. The beam characteristics are greatly affected by the shape of the subarray structure as well as the weight of subarray in digital beamforming. So in this paper, the method to generate subarray structures by using recursive element exchanging method and the method to optimize subarray structures that can minimize sidelobes of operating beams are proposed. Additionally it presents the result to find the optimized subarray structure to minimize the maximum sidelobe of monopulse beam and pencil multi-beam respectively or simultaneously which are commonly used for digital beamforming by applying the algorithm propsed in this paper.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.6
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• pp.1465-1474
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• 1994

For a vertical wall with standing waves on its front face, the unsteady flow in a flow conduit installed through the wall is analyzed. A nonlinear standing wave theory making use of Fourier expansion is applied, and the results are verified by a hydraulic experiment. It is found that the nonlinear theory better predicts the behavior of the flow compared to its linear counterpart. The investigation of the water transmissibility through the conduit shows that the variation of the flow rate becomes larger as the standing wave height and period increase and as the length of conduit decreases. The relationship is presented by a nondimensional equation. The net flow gain per one wave period, which is directly related to water exchanging capability of the conduit, appears to be negative in both theory and experiment when the conduit is located near the bottom. The maximal flow gain occurs in the conduit whose mouth is located at the still water level. In addition, it is shown that the longer wave period and the shorter conduit length are more effective in the water exchanging performance.